Underfeed-stoker boiler



n. s. JACOBUS.

UNDERFEED STOKER BOILER.

APPLICATION FILED NOV. 4,1915.

1,365,321. Patented Jan. 11,1921.

2 SHEETS-SHEET I- A TTOR/VEY f I D. S. JACOBUS.

UNDERFEED STOKER BOILER.

APPLICATION FILED NOV. 4. 1915.-

1,365,321, Patented Jan. 11, 1921.

2 SHEETS-SHEET 2.

WITNESSES. l/VVE/VTOR ATTORNEY-f. 1

UNITED STATES PATENT OFFICE.

DAVID S. JACOBUS, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO THE BABOOCK & 'WILGOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

UNDERFEED-STOKER BOILER.

Specification of Letters Patent.

Patented Jan. 11, 1921.

To all whom it may concern:

Be it known that I, DAvIoS. JACOBUS, a citizen of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented a new and useful Improvement in Underfeed- Stoker Boilers, of which the following is a full, clear, and exact description, reference being bad to the accompanying drawings, forming part ofthis specification.

My .invention relates to the application of underfeed stokers to water tube boilers, particularly those of the well-known Babcock & Wilcox type, and is designed to provide a furnace which will give good efliciency, and atthe same time overcome the clinker difficulties which have existed in the practical service of such underfeed stokers.

In the drawings, Figure 1 is a sectional side elevation showing a Babcock & Wilcox boiler and underfeed stoker constructed in accordance with my invention; and Fig. 2

.is a sectional front view of two boilers in a battery. setting, the section being on the line 22 of I.

In these drawings, 2 represents the underfeed stoker, which may be of any usual commercial type, and is preferably set farther beneath the boiler than in ordinary practice.

The front and rear walls 3 and 4 of the furnace diverge upwardly, each being inclined upwardly and outwardly. This construction of the front and rear walls avoids the tendency which vertical walls in such structures heretofore had of leaning or bulging inwardly during use.

In connection with the underfeed stoker, I employ water-boxes at the sides of the furnace around the stoker grate, these boxes being connected to the boiler circulation. The side water-boxes 5 are preferably inclined rearw'ardly and downwardlyalpng the side furnace walls. These boxes may extend through the rear wallof the furnace chamber, and their rear ends are connected by bent tubes or pipes 6 to the boiler muddrum 7.. The front ends of these side boxes are nippled to the front cross-box 8, extending across the front of the furnace chamber above the grate, and from the box 8 the water flows upward through a number of tubes 9 into the lower part of the front boiler headers 10.

The rear cross-water-box 11 is preferably located below the level of the front crossbox 8, and at the rear of the dumping plate 2' of the stoker; and is partially embedded in the rear furnace wall, this box being connected by pipes 12 extending throughthis wall and up to the boiler mud-drum 7. From this rear water-box 11 the water flows upwardly through the pipe 13, which is curved upwardly and forwardly at the side of the furnace, into the lower part of the front boiler headers 10.

It will be noted that the downtake and inlet water pipes for the furnace water-boxes are located in a relatively cool portion of the setting, whereas the uptake water pipes for these boxes are subjected to the radiant heat of the fire and to the hot furnace gases, thus causing an efficient circulation through these boxes. Instead of connecting the pipes 6 and 12 to the mud-drum they may be connected to the lowermost portion of the rear headers 14: of the boiler if desired.

Blow-off connections 16 are provided for blowing out any mud which may accumulate in the side boxes 5, and blow-off connections 17 are also provided for blowing out any mud which may accumulate in the cross-boxes 11.

The boiler shown is of the usual Babcock & Wilcox type having a longitudinal steam and Water drum 18 connected to the front and rear headers '10 and 14. The bank of the water tubes 19 is preferably inclined.

rearwardly and downwardly between the headers, and the baflles 20 and .21 for the boiler tubes are preferably arranged as shown, so that the first u ward pass is gradually narrowed upwardly. and the second downward pass is narrowed downwardly. A superheater is shown at 22, over which the gases pass, betweenthe first and second pass throu h'the tubes. The gases protection afforded through the water boxes;-

A strong circulation is set up throu h these water boxes, thus preventing-their urning out. The excess air from below the grate passes upwardly through the dumping plates 2 at the rear of the stoker, flows up at the rear of the furnace and is thrown forward by the roof baffling around the lower row of tubes below the second pass and caused to mingle with the gases from the front of the stoker, thus giving highly eflicient combustion.

What I claim and desire to secure by Letters Patent of the United States is 1. The combination of a boiler with an underfeed stoker furnace, said furnace having inclined side water boxes connected to the boiler circulation, a transverse front water box contiguous to the front wall of the furnace and to the front of the fire bed having its end portions connected to the upper ends of the side water boxes, and a row of tubes at the furnace side of the front wall and arranged to protect said wall from the heat ofthe furnace, said tubes connecting the transverse front water box with the boiler circulation.

2. The combination of a boiler with an underfeed stoker furnace, said furnace having inclined side water boxes connected to the boiler circulation, a transverse front water box contiguous to the front wall of the furnace and to the front of the fire bed 'having its end portions connected to the upper ends of the side water boxes, and a row of tubes at the furnace side of the front wall and arranged to protect said wall from the heat, of the furnace, said tubes connecting underfeed stoker furnace, a rear furnacewall, a water box extending across the back of the furnace chamber and connected. to the boiler circulation, side water boxes also connected to the boilercirculation, separate inlet pipes for each of saidboxes located outside of the furnace chamber and beyond said wall, and separate outlet connections for each of said boxeslocated within the furnace chamber and subjected to the radiantheat of the fire and to the hot furnace gases.

5. The combination of a boiler with an underfeed stoker furnace, a rear furnace wall, a water box extending across the back of the furnace chamber, side water boxes extending along the sides of the fire bed and connections extending to the boiler circulation.

6. The combination with a water tube boiler having a horizontally inclined bank of tubes connected to uptake and downtake headers, of an underfeed stoker furnace beneath the bank of tubes, a rear furnace wall, a rear water box extending across the back of the furnace chamber, side water boxes extending along the sides of the fire bed and through said rear wall, inlet connections to said boxes from the downtake head ers, and outlet connections for said boxes entering the uptake headers and within the furnace chamber.

7. The combination with a water tube boiler having a horizontally inclined bank of tubes connected to uptake and downtake headers, of an underfeed stoker furnace be- ,neath the bank of tubes, a rear furnace wall extending upwardly to the bank oftubes, a roof wall extending forwardly from said rear wall, a transverse baflie extending from said roof wall, a rear water box across the back'of the furnace chamber and connected to the boiler circulation, side water boxes extending through said rear wall and also connected to the boiler circulation, an outlet connection for said rear box extending through the furnace chamber from the rear wall to the uptake headers, and outlet connections for said side boxes extending upwardly at the front of the furnace chamber and also connected to the uptake headers.

8. The combination with a water tube boiler having a horizontally inclined bank of tubes with end connections leading,up ward to a steam and water drum, of an underfeed stoker beneath the bank of tubes, a rear furnace wall, side water boxes inclined at the angle of the fire bed and extending through the rear furnace wall, the lowermost ends of these boxes havin water connections leading from the downta e connections from the steam and water drum to the lowermost ends of the boiler tubes, and the upper ends of the side water boxes having steam and water connections leading to the lowermost ends of the uptake connections which lead from -the uppermost ends of the boiler tubes to. the steam and water drum, the water connections which lead to the lowermost ends of the side water boxes being placed in a relatively cool portion of the setting, and the steam and water connectionswhich lead from-the uppermost ends of the side water boxes being exposed to the radiant heat of the fire and to the hot furnace gases.

9. The combination with a water tube boiler having a horizontally inclined bank of tubes with end connections leading upward to a steam and water drum, of an underfeed stoker furnace beneath the bank of tubes, a rear furnace wall, the stoker having dumping plates contiguous to the rear furnace wall, a water box placed within the rear furnace Wall adjacent to the stoker dumping plates, said water box being connected at one end with the downtake connections from the steam drum to the boiler tubes by tubes placed in a relatively cool portion of the setting, and at the other end with the uptake connections from the boiler tubes to the steam drum by tubes exposed to the radiant heat of the fire and to the hot furnace gases.

10. The combination with a Water tube boiler having a horizontally inclined bank of tubes with end connections leading upward to a steam and water drum, of an underfeed stoker furnace beneath the bank of tubes, said furnace having a transverse front water box contiguous to the front wall of the furnace and to the front of the fire bed, said water box being supplied with water from the boiler at its end portions, and tubes at the furnace side of the front wall connecting the transverse front water box with the front uptake connections of the water tubes.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

DAVID S. JACOBUS.

Witnesses EUGENE I TERRY, EDITH CAMP. 

